Understanding atopic dermatitis
Affecting up to 20% of children and 5%-10% of adults, atopic dermatitis is not limited to visible symptoms. It leads to sleep disorders, anxiety and increased vulnerability to skin infections.
Biologically, the disease is characterised by an excessive inflammatory response, dominated by type 2 T helper lymphocytes (Th2). Cytokines such as IL-13 and IL-31 inhibit the expression of filaggrin, a protein essential for the cohesion of the skin barrier, leading to extreme dryness of the skin.
Furthermore, an imbalance in the skin microbiome, often marked by the proliferation of Staphylococcus aureus, aggravates inflammation and skin reactivity.
New approaches in cosmetics and dermatology
Faced with these challenges, the cosmetics and pharmaceutical industries are investing in advanced biological models to better understand disease and test product efficacy. Among these innovations, Eurofins Cosmetics & Personal Care recently developed ATODERM Skin, an ex vivo model based on human skin explants treated with a mixture of cytokines to faithfully reproduce the molecular and structural characteristics of atopic dermatitis.
- Transcriptomic profiling: Through comparative analysis with in vivo biopsies, we identified three main molecular pathways mirroring real-life atopic dermatitis conditions: inflammation, skin barrier function, and lipid metabolism.
- Real-time PCR-based array: A targeted analysis of 30 key genes implicated in atopic dermatitis pathology.
- Protein-level validation: Using microscopy, we confirmed a significant decrease of filaggrin expression, reinforcing the model’s relevance for preclinical evaluation.
This approach makes it possible to test the efficacy of new molecules in the laboratory before moving on to clinical trials.
Clinical testing: Tolerance and efficacy assessment
In addition to biological models, the clinical evaluation of products for atopic skin is based on rigorous methodologies. The studies include:
- Tolerance tests: Patch tests, repeated application tests (ROAT) and use tests to identify the risks of sensitisation.
- Efficacy studies: Parameters such as hydration, barrier function, redness reduction, and itch relief are meticulously evaluated. Standardized scoring systems like SCORAD, EASI, and IGA ensure objective comparisons across different products.
- Quality-of-life questionnaires: Providing insight into the real impact of skin care solutions on daily well-being.
Emotional tests: Objective assessment for atopic skin
A significant innovation in in vivo assessment is Galvanic Skin Response (GSR), which characterises skin sensitivity and objectively evaluates the calming or soothing effects of cosmetic products.
GSR detects changes in skin conductivity triggered by sweat gland activity in response to sensory stimuli. For example, a reduced reaction to heat exposure on atopic skin post-product application confirms a formula’s soothing effect. This method provides brands with an unbiased metric to validate product claims related to comfort and irritation relief.
Thanks to increasingly accurate testing methods, the cosmetics and dermatology industry now has the tools it needs to develop more effective, safe and appropriate solutions for atopic skin,
helping to improve the quality of life of those affected. With its in-depth expertise and cutting-edge technologies, Eurofins C&PC supports this industry in the quest for innovative solutions,
fostering a deeper understanding of this complex and multifactorial disease and providing tailor-made solutions to improve the daily lives of those affected.